The present invention relates generally to the field of electronic temperature sensing and control and more particularly to temperature sensing by the use of electrical bridge networks. More particularly, the present invention relates to the combination of temperature sensing electrical bridge networks with circuitry providing digital control signals used to actuate machinery or equipment.
Thermostats used to control the operation of machinery and equipment have generally been designed around a mechanical means for temperature sensing This mechanical means usually takes the form of a bimetallic strip configured in such a manner that expansion or contraction of the strip would trigger a mechanical switch. With repeated industrial use, the contacts of such switches tend to deteriorate and malfunction. Applicant's electronic thermostat however contains no mechanical parts to deteriorate or malfunction and provides increased stability dispite repeated shock, vibration, and aging. Because the controls for most machinery and equipment now use standard digital logic levels, applicant's electronic thermostat has been designed to provide a standard logical "on" signal when the temperature of the sensor rises above a preselected value.
Although resistor bridge networks and even those including one of more diodes have been used for the linear measurement of temperature, such diode bridge networks have not been combined with the necessary circuitry to produce the digital control signals necessary to produce an electronic thermostat.